Disclaimer: I bought all of the above recently and am comparing them to my older system of three years ago.
4890 Vapor X - The relative performance of this card has been done to death in the press, so I won't go into the detailed spec. othjer than to say it is a revelation from the old 8800GT. The performance jump to the new card drew Ooooh's and Aaaaaah's from the kids. What I can say, is that this card is damn near silent. It is certainly quieter than my 8800GT. It's a good looking piece of kit, easy to fit, and is of average length. This translates to choosing the bay for the HDD is important, as both of the PCIE power connectors are at the rear of the card and will foul the cables to the back of HDD if they are in the same plane. This is hardly an issue in the Antec 300, or indeed in most cases, with multiple bays. Those people with a RAID or similar might want to check with a ruler. At the current price level, it represents huge value for money.
Antec 300 - I'm sure that the readers here are familiar with this case, but I think it's worth bringing it back to the attention of you all. It's cheap, roomy, readily available and has an understated look that I far prefer. It was easy for a complete novice for myself to use, as all connectors are clearly labelled for the top mounted USB, Power and activity LEDs. My only gripe, and it's a small one, is that the two exhaust fans supplied are not as quiet as some models, it's not intrusive, but they would benefit from a replacement with something a little more upmarket. They certainly work, however, and heat is not an issue with the quantity of air being pulled through the system. Heh, I actually quite like the sound of the fans winding down on shut down of the system.
LG W2343T - My older monitor was a 19" Viewsonic, and the LG demonstrates how far things have progressed in the last few years. The monitor presents gorgeous images with deep blacks and no apparent blur, even the biggest firefights. I bought this screen on the basis of it's price and recommendation and have not been disappointed with it's quality. There were no dead or stuck pixels and the stand provides swivel and a few degrees of tilt, but that's about it. If you're very tall you may want to look at an arm or a couple of telephone books. I had the opportunity recently to see one side by side with a Samsung panel, and I can honestly say that I preferred the LG. It may be worth noting that the particular model I bought had a VGA and DVI connector but no HDMI. This isn't an issue for me, but YMMV. No doubt there are better panels with higher resolution at this price point now, but I am very happy with the purchase.